Quick answer
MSG (E621) has no animal ingredient, but uncertified MSG is doubtful. The glutamate is made by bacterial fermentation of plant sugars or starch; the doubt is the process, because the bacteria's growth medium can be prepared with animal-derived enzymes. Halal-certified MSG is halal. Its usual companions, disodium inosinate (E631) and disodium ribonucleotides (E635), carry a bigger doubt: they can be made from meat or fish (the leading producers say they use fermentation), and labels rarely say which.
The MSG Panic, and the Real Question
Few ingredients trigger as much "is this halal?" anxiety as the flavour enhancers clustered at the end of a savoury snack's ingredient list: monosodium glutamate (E621), disodium inosinate (E631) and disodium ribonucleotides (E635). They're in crisps, instant noodles, stock cubes, seasoning powders and most savoury snacks on the shelf.
The three are doubtful for different reasons. MSG's own ingredient is not animal-derived, so its doubt is about how it is made. E631 and E635 can come from animal sources outright. Knowing which is which tells you what to look for on the pack.
What Flavour Enhancers Do
Flavour enhancers boost the savoury, mouth-filling "umami" taste without adding a flavour of their own. MSG provides the base umami hit; the ribonucleotides (E627, E631, E635) multiply it, which is why manufacturers combine them: a little of each goes a long way.
The Verdict for Each Code
All four are doubtful without certification, but not for the same reason:
| E-Number | Name | Halal status | Why |
|---|---|---|---|
| E621 | Monosodium glutamate (MSG) | Suspect | Made by bacterial fermentation of starch or sugar, with no animal ingredient. The growth medium can involve animal-derived enzymes. Halal if certified. |
| E627 | Disodium guanylate | Suspect | Usually made by fermentation, but can be extracted from fish or meat. Source rarely stated. |
| E631 | Disodium inosinate | Suspect | Can be derived from fish or meat; the leading producers say they use fermentation. Verify the source. |
| E635 | Disodium ribonucleotides | Suspect | A blend of E627 and E631, so it inherits the same animal-source risk. |
The Big Ones, Explained
E621: Monosodium Glutamate (MSG)
Commercial MSG is made by fermenting a carbohydrate source such as sugarcane molasses, corn or cassava starch with bacteria, the same broad process behind vinegar, soy sauce and yoghurt. The glutamate itself is not animal-derived. The doubt sits upstream, in the process: in January 2001 PT Ajinomoto Indonesia recalled its MSG after Indonesia's MUI ruled it haram, because a pork-derived enzyme had been used to prepare the bacteria's growth medium. A label cannot tell you how the medium was prepared, so the halal additive listing our app follows marks MSG as doubtful unless it is certified. Halal-certified MSG is widely sold, and products certified by a recognised body have had this checked. See the E621 halal verdict.
E631: Disodium Inosinate
This is the one to watch most closely. Disodium inosinate is a powerful umami booster that can be produced from meat or fish, although the leading producers say they make it by microbial fermentation on plant-based media. When the source isn't stated, it's doubtful (mashbooh). It's also almost never used alone: if you see E631, MSG and often E635 are usually close by. See the E631 halal verdict.
E635: Disodium Ribonucleotides
E635 is usually a 50/50 blend of disodium guanylate (E627) and disodium inosinate (E631). Because it contains E631, it carries the same animal-source ambiguity and is best treated as doubtful unless a halal source or certification is stated. See the E635 halal verdict.
Why E631 and E635 Travel Together with MSG
You'll constantly see "E621, E627, E631" or "MSG, disodium ribonucleotides" listed as a trio. That's because the ribonucleotides dramatically amplify MSG's umami effect, so manufacturers get more savoury impact for less additive. The practical takeaway: when you see this trio, one halal certification answers all three; without one, the whole group is doubtful.
How to Tell If a Flavour Enhancer Is Halal
- Look for a halal certification logo first. Certification covers MSG's fermentation process and the source of E627, E631 and E635 in one step.
- No logo? Look for a stated source ("from vegetable/microbial origin"). Without one, treat MSG and the ribonucleotides as doubtful.
- Country matters. Products made for Muslim-majority markets often use halal-certified MSG and microbial ribonucleotides.
- Scan it. A barcode or photo scan with Halal Food AI flags E621, E631 and E635 automatically and tells you whether the product declares a halal source.
Frequently Asked Questions
Is MSG halal?
MSG (E621) contains no animal ingredient: it is made by bacterial fermentation of plant carbohydrates. But the fermentation can use a growth medium prepared with animal-derived enzymes, as in Indonesia's 2001 Ajinomoto recall, so uncertified MSG is doubtful. Halal-certified MSG is halal.
Is E621 halal?
E621 is monosodium glutamate (MSG). It is doubtful unless halal-certified, because the label does not show how its fermentation was carried out.
Is disodium inosinate (E631) halal?
E631 is doubtful (mashbooh) by default because it can be made from fish or meat and labels rarely state the source. It's halal only when the product states a microbial/plant source or carries halal certification.
Why are E631 and E635 more of a concern than MSG?
MSG's doubt is only about its fermentation process; the glutamate itself is not animal-derived in commercial production. E631 (and E635, which contains it) can be made from animal or fish by-products directly, and labels rarely state the source, so scholars treat them as doubtful until the source is confirmed.
Need the verdict on another code? Browse the full E-code halal reference: every additive with a clear halal, suspect, or not-halal verdict and the reason behind it.